Connector

ABSTRACT

A connector is provided for selectively coupling one or more lines or wires ( 19′, 19″ ) to a receiving and/or transporting device ( 27 ). The connector comprises at least one line or wire receiving ferrule ( 7 ) having a plurality of line and/or wire receiving holes ( 17′ - 17″ ) each capable of receiving one of said one or more lines or wires ( 19′, 19″ ), wherein said connector further comprises a body ( 3 ) for receiving said ferrule ( 7 ) and clamping means ( 9, 11 ) for exerting a force on said ferrule ( 7 ) in order to simultaneously exert a line or wire clamping force on all said line and/or wire receiving holes ( 17′ - 17″ ). In this way all the fluid lines or wires can be clamped at the same time.

FIELD OF THE INVENTION

The present invention relates to devices of the type mentioned in thepreambles of the independent claims.

PRIOR ART

Much effort is being expended on producing microfluidic devices foranalysing small volumes of liquids. Many companies are producingso-called “labs on a chip”. Such a lab on a chip typically comprises adisk or block (a “chip”) made of an inert transparent material, e.g. aplastic, in which microchannels are formed. Samples of substances to beanalysed can be inputted to these microchannels and these microchannelslead to chambers where the samples can be reacted with reagents. Theresults of the reactions may be observed through the transparent disc orblock walls and/or the products of the reactions may be output from thechip for further processing or analysis. Thus there is a need to connectthe chips to input and output interfaces. This poses many problems asthe microchannels are small, typically a few micrometers in width ordiameter, and it can be difficult to align input devices with them.Additionally some of the input devices, e.g. liquid chromatographs, workat high pressures and it has proven to be difficult to prevent leakagewhen using such input devices. This is particularly true when verynarrow diameter silica tubes are used as the pressure drop over them isvery high and therefore pressures are used which are tens or hundreds oftimes greater than atmospheric pressure. Similar problems occur whenconnecting pneumatic systems and hydraulic systems. Additionally, it isoften difficult to satisfactorily connect electrical wires, opticalcables and the like to devices such as fluidic chips.

SUMMARY OF THE INVENTION

According to the present invention, at least some of the problems withthe prior art are solved by means of a connector device having thefeatures present in the characterising part of claim 1 and a connectorferrule having the features mentioned in the characterising part ofclaim 7. Further improvements are obtained by devices having thefeatures mentioned in the dependent claims.

BRIEF DESCRIPTION OF THE FIGURES

The following figures show an illustrative, non-limiting example of anembodiment of the present invention in which:

FIG. 1 shows a lateral cross-section of a first embodiment of aconnector in accordance with the present invention;

FIG. 2 shows a view from above of the connector of FIG. 1; and,

FIGS. 3 a) and 3 b) show schematically other shapes for connector bodiesand ferrules in accordance with the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS ILLUSTRATING THE INVENTION

In this example of an embodiment of the invention, it will beillustrated how fluid transporting capillaries can be connected to afluid receiving and transporting chip. It should be noted that thepresent invention is not restricted to use such capillaries and chipsbut may also be used for connecting electrical wires to a component orother wires, fibre optic wires to a component or other wires, hydrauliclines to a component or other lines, etc. A connector 1 in accordancewith the present invention is shown in section in FIG. 1 and a view fromabove of the connector of FIG. 1 is shown in FIG. 2. Connector 1 has acylindrical connector body 3 with an tapered axial through hole 5. Body3 is made of any suitable material, such as stainless steel, which isable to withstand the forces exerted during assembly and operation ofthe connector. A connector ferrule 7 in the shape of a truncated coneand adapted to fit into through hole 5 with its narrow end 7A extendingthrough the narrow end of through hole 5 is positioned in through hole5. Ferrule 7 is designed to be less rigid than the body 3, andpreferably is made of a machinable plastic, for example PEEK(essentially polyetheretherketone) or the like. Ferrule 7 is retained inconnector body 3 by a ferrule presser plate 9 which can be attached byattaching means such as bolts or screws 11 onto connector body 3 at theend where the though hole 5 is widest. Ferrule presser plate 9 has apressure surface 9A which faces towards, and is intended to fit andpress against, the end surface 8 of the widest end 7B of connectorferrule 7. The force that presses connector ferrule 7 into through hole5 can be adjusted by adjusting the force which the attaching means 11exerts on pressure plate 9. Ferrule presser plate 9 is designed to bemore rigid than the connector ferrule 7. As ferrule presser plate 9 isbolted towards hole 5, its pressure surface 9A comes into contact withthe widest end surface 7B of connector ferrule 7 and consequently itforces the tapered surface 7C of connector ferrule 7 against the taperedportion 5B of through hole 5. Connector ferrule 7 can thereby becompressed between the tapered portion 5B of through hole 5 and ferrulepresser 9. As both body 3 and presser plate 9 are both more rigid thanferrule 7 then ferrule 7 deforms first under the compression forces.

Ferrule presser plate 9 has a central opening 13, and ferrule 7 has acylindrical cavity 15 at its widest end. This cavity 15 is substantiallyconcentric with the central opening 13 in ferrule presser plate 9. Thelower end of cavity 15 contains a plurality of capillary receivingthrough holes 17′, 17″-17 ^(N) (only two of which are shown in FIG. 1for the sake of clarity) that extend from the base of cavity 15 to thebottom surface of ferrule 7. Capillary receiving through holes 17′,17″-17 ^(N) are preferably equidistantly spaced apart and arranged in acircle centred on the centreline of ferrule 7, or arranged in anotherregular pattern, so that when ferrule 7 is compressed then the forcesthat act on each capillary receiving through holes 17′, 17″-17 ^(N) aresimilar. The upper ends (i.e. the ends which open out into the cavity15) 17A of capillary receiving through holes 17′, 17″-17 ^(N) aretapered so that they become narrower towards the bottom and atapproximately half way along their depth they become cylindrical, sothat the lower ends 17B of capillary receiving through holes 17 arecylindrical. The diameter of at least a portion of the lower ends 17B ofcapillary receiving through holes 17 when uncompressed is substantiallythe same as, or greater than, the diameter of the fluid tubing such ascapillaries 19′, 19″-19 ^(M) with which the connector 1 is intended tobe used, e.g. 0.36 mm if silica capillaries are used or 0.18 mm ifmicro-silica capillaries are used, so that the capillaries can beinserted a distance into the lower ends 17B. As the clamping of thecapillaries by the ferrule takes place in this portion of the lower ends17B, preferably the diameter of this portion should be sufficientlylarge so that the capillaries can be easily inserted into this portionand should be sufficiently small such that even when the ferrule isunclamped the capillaries are lightly held in the ferrule in order toprevent them being accidentally detached during handling of the ferrule.It is possible to provide a capillary receiving though hole with astepped and/or tapering diameter with an upper portion with a diameterof about 0.36 mm and which is stepped and/or tapered down to a diameterof about 0.18 mm so that the a ferrule could be used with both 0.36 mmdiameter capillaries and 0.18 mm diameter micro-capillaries. Optionally,the bottom of each capillary receiving through hole 17 may be providedwith a ledge 17C which prevents the passage of capillaries. The heightof the ledge should be chosen to prevent the capillaries 19′, 19″ frombeing inserted too far into through holes 17′, 17″-17 ^(N) andprojecting out of the narrow, bottom surface 10 of ferrule 7.

In order to make the connector as small as possible, the distancebetween centres of the capillary receiving through holes 17′, 17″-17^(N) can be small, for example of the order of 0.5 mm if silicacapillaries with an outside diameter of 0.36 mm are used and 0.25 mm ifmicro-silica capillaries (outside diameter 0.18 mm) are used. Thetapered upper ends 17A of capillary through holes 17 act as funnels andmake it easier to thread the capillaries 19′, 19″ in the capillaryreceiving through holes 17. As ferrule presser plate 9 pushes connectorferrule 7 down into through hole 5, connector ferrule 7 is compressedbetween ferrule presser 9 and the tapered portion 5B of through hole 5.As ferrule 7 is less rigid than body 3 which has the tapered portion 5Bof through hole 5 formed in it, the tapered lower end 7B of connectorferrule 7 deforms. One of the few directions in which the material candeform is towards the inside of the capillary receiving through holes17′, 17″-17 ^(N). This causes a radial force towards the centre of eachcapillary receiving through hole 17′, 17″-17 ^(N). This results in aclamping force on the capillaries 19′, 19″-19 ^(M) introduced into thethrough holes 17′, 17″-17 ^(N). This clamping force can be increased byclamping ferrule presser 9 closer to through hole 5 and can easily beenough to form a fluid tight seal which can resist over 1000 bar—apressure which has been difficult to achieve in prior art connectors foruse in high pressure liquid chromatography, mass spectrometry andelectrophoresis and the like. When the capillary receiving holes arearranged symmetrically, for example as shown in FIG. 2, the clampingforce on each capillary is substantially equal.

Connector body 3 is provided with slots 23 in its side walls 25 in orderto allow a fluid receiving and/or transporting device such as a chip 27to be placed in contact with the end surface 10 of the narrow end 7A ofconnector ferrule 7. Chip 27 is provided with microchannels 29′, 29″which are connected to openings 31′, 31″-31 ^(M) in the top surface 27Aof chip 27. In a preferred embodiment of the present invention thenumber of openings 31′, 31″-31 ^(M) preferably is equal to the number ofcapillary receiving through holes 17′, 17″-17 ^(N) and the openings 31′,31′-31 ^(M) are positioned so that they can all be simultaneouslyaligned with capillary receiving through holes. It is also conceivableto have more openings than capillaries and vice versa. Preferablyconnector ferrule 7 and chip 27 are provided with complementing guidepins and holes (not shown), or co-operating guide surfaces in order tofacilitate and ensure correct alignment. Alternatively, the throughholes 17 may be made without ledges 17C and the end of at least onecapillaries allowed to project out of the bottom of at least one throughhole in order to act as a guide pin.

In order to provide a sealing force between the capillary receivingthrough holes 17′, 17″-17 ^(N) and openings 31′-31 ^(M), chip 27 issupported on a movable support plate 35. Support plate 35 is positionedon the opposite side of the chip to the connector ferule 7 andpreferably the face of support plate 35 in contact with the chip has ashape and dimensions similar which are adapted the face of the ferrule 7in contact with the opposite face of the chip and is positioned directlyunderneath the ferrule such that no damaging stress concentrations areformed in the chip when it is clamped between the ferrule 7 and supportplate 35. The support plate 35 is provided with compression forceproducing means such as a spring 37 positioned between support plate 35and a movable compression plate 39, and means such as bolts 41 formoving the compression plate 39 towards or away from support plate 35.Bolts 41 can be used to adjust the force that support plate exerts onchip 27—moving compression plate 39 closer to chip 27 increases theforce between chip 27 and connector ferrule 7 and vice versa. The spring37 allows the force exerted by the bolts 41 to be finely controlled. Theslots 23 are deeper than the thickness of a chip 27 so that when ferrule7 and support plate are clamping a chip 27 in its working position thenchip 27 is not in contact with any part of body 3. In other words thereis a gap 51 between the upper surface of chip 27 and the upper interiorsurfaces of slots 23 and a gap 53 between the bottom surface of chip 27and the lower interior surfaces of slots 23. This means that chip 27 issupported by ferrule 7 and support plate 35 which maximises the clampingforces to where they are needed and prevents the occurrence ofasymmetric clamping forces which could otherwise occur if chip 27 cameinto contact with the side walls 25. Support plate 35 and compressionplate 39 could be made of a transparent material in order to facilitatealignment of the components and to allow easy visual checking of thealignment.

Ferrule 7 is preferably provided with means such as a key-way and key orprojections adapted to fit in corresponding depressions in connectorbody 3 in order to for preventing it from rotating once it has beenplaced in body 3, in order to prevent capillaries from becoming twistedand to ensure that the capillaries are connected to the intended openingon the chip when in use. This can be achieved in many different ways,for example by making it asymmetric, e.g. by providing a projecting stub(not shown), and by providing body 3 with a complementary recess (notshown), so that ferrule 7 can be held fixed against rotation withrespect to body 3.

A connector in accordance with the present invention can be assembled inthe following way: the operator threads the required number ofcapillaries 19′-19 ^(M) through the central opening 13 of ferrulepresser plate 9. A first capillary 19′ is then introduced into cavity 15of connector ferrule 7, fed into the tapered upper end 17A of a firstthrough hole 17′ and pushed approximately all the way into the lower end17B of the through hole 17′ until it reaches the ledge 17C near thebottom of the through hole 17′. This is repeated for a second capillaryand a second through hole, until all the capillaries 19′-19 ^(M) havebeen mounted in their respective through holes 17′-17 _(N). Theconnector ferrule 7 is then positioned in the through hole 5 withtapered bottom end 7B located in the tapered lower end 5B of throughhole 5. The ferrule presser plate 9 is positioned on top of connectorferrule 7 and bolts 11 tightened towards body 3 so that ferrule 7 ispressed into the tapered bottom end 5B of through hole 5 so that itdeforms enough such that the through holes 17′, 17″-17 ^(N) becomenarrower and grip the capillaries 19′-19 ^(M). A chip 27 can then beinserted through slots 23 and aligned with its openings 31′, 31″-31 ^(M)each directly aligned with one of the through holes 17′, 17″-17 ^(N).Bolts 41 can then be tightened until chip 27 is in contact with thenarrow end surface 10 of ferrule 7. Further tightening of bolts 11and/or 41 will increase the sealing force between narrow end surface 10and the chip 27.

It is conceivable to provide a connector in accordance with the presentinvention in which the ferrule presser plate is provided with aplurality of axial guide holes for capillaries instead of a centralcavity. Each guide hole would have an outlet at the bottom of theferrule presser plate and the outlet would be arranged to align withcapillary receiving through holes in the connector ferrule. Theconnector ferrule and ferrule presser plate could be provide withco-operating alignment means such as a projection on one of thesecomponents which fits into a recess on the other component in order toensure correct alignment

While the embodiment of the present invention illustrated in the figuresdepicts a connector in which the connector ferrule and the chip haveflat mating surfaces, it is of course possible to use other surfaceshapes which can seal against each other. For example, a connectorferrule can have a concave surface and a chip a matching convex surface(or a surface which becomes convex when compressed during use), or viceversa. Additionally, it is also possible to use a plurality of ferrulesin one connector body in order to connect fluid lines to a plurality ofchips simultaneously, or to connect fluid lines to a plurality ofregions on a single chip simultaneously.

Additionally, it may be advantageous to provide the connector ferrulewith a narrow end surface which, when unloaded, is concave from itscentre to the radial distance corresponding to the part of the throughholes 17′, 17″-17N which is nearest the centre in order to relievestress at the interface between the chip and the connector ferrule whenin use.

Furthermore, it is not necessary that the through hole in the connectorbody and the ferrule have matching tapered surfaces—it is conceivable touse a cylindrical ferrule 7′ in a tapered hole 5′ as shown schematicallyin FIG. 3 a). It is also conceivable to use a ferrule 7″ with aquadratic cross-section in a tapered quadratic hole 5″ as shownschematically in FIG. 3 b). With the add of the principle illustrated bythe above examples, other complementary shapes for the hole and ferrulewhich can produce a compression force on the ferrule as it is clampedare readily conceivable to the skilled person.

While the invention ahas been illustrated by am embodiment in which onlyfluid lines are held in the ferrule, it is conceivable to provide theferrule with electrical and/or optical wire receiving holes in additionto, or instead of, fluid line receiving holes. This would allow thesimultaneous connection of electrical and optical circuits.

The above mentioned example of conceivable embodiments are intended toillustrate the present invention and are not intended to limit the scopeof protection claimed by the following claims.

1. A connector (1), for selectively coupling one or more of input and/oroutput lines (19′, 19″) and/or wires to a receiving and/or transportingdevice (27), comprising at least one line and/or wire receiving ferrule(7), said ferrule (7) having a plurality of line and/or wire receivingholes (17′-17″) capable of receiving one of said one or more lines orwires (19′, 19″), a body (3) for receiving said ferrule (7), andclamping means (9, 11) for exerting a force on said ferrule (7) in orderto simultaneously exert a line and/or wire clamping force on all saidline and/or wire receiving holes (17′-17″).
 2. The connector of claim 1,further comprising means (5B) for radially compressing said line and/orwire receiving holes (17′-17″).
 3. The connector of claim 1, whereinsaid ferrule (7) is held in a connector body (3) which is more rigidthan said ferrule (7).
 4. The connector of claim 1, wherein said ferrule(7) is made of PEEK.
 5. The connector of claim 1, wherein a portion ofeach of said line and/or wire receiving holes (17′-17″) has a diameterof 0.36 mm.
 6. The connector of claim 1, wherein a portion of each ofsaid line and/or wire receiving holes (17′-17″) has a diameter of 0.18mm.
 7. The ferrule for use in the connector of claim 1, wherein saidferrule (7) is formed as a truncated cone or another truncated taperedbody and it contains a plurality of line and/or wire receiving holes(17′-17″).
 8. The ferrule of claim 7, wherein upper ends (17A) of saidline and/or wire receiving holes (17′-17″) are tapered so that theybecome narrower towards the bottom.
 9. The ferrule of claim 5, whereinthe lower ends (17B) of said line and/or wire receiving holes (17′-17″)are cylindrical.
 10. The ferrule of claim 5, wherein said line and/orwire receiving holes (17′-17″) are arranged symmetrically in saidferrule (7).